Free Radical Scavenging Activity Assay Research Articles

An assessment on the role of endophytic microbes in the therapeutic potential of Fagonia indica

BackgroundNatural products of animals, plants and microbes are potential source of important chemical compounds, with diverse applications including therapeutics. Endophytic bacteria that are especially associated with medicinal plants presents a reservoir of therapeutic compounds. Fagonia indica has been recently investigated by numerous researchers because of its striking therapeutic potential especially in cancer. It is also reported that endophytes play a vital role in the biosynthesis of various metabolites; therefore we believe that endophytes associated with F. indica are of crucial importance in this regard. The present study aims successful isolation, molecular identification of endophytic bacteria and their screening for bioactive metabolites quantification and in vitro pharmacological activities.Methods16S rRNA gene sequencing was used for the identification of isolated endophytic bacteria. Methanolic extracts were evaluated for total phenolic contents (TPC), total flavonoids contents (TFC), DPPH free radical scavenging activity, reducing power and total anti-oxidant assays were performed. And also screened for antibacterial and antifungal activities by disc diffusion method and their MIC were calculated by broth dilution method using microplate reader. Further, standard protocols were followed for antileishmanial activity and protein kinase inhibition. Analysis and statistics were performed using SPSS, Table curve and Origin 8.5 for graphs.ResultsBacterial strains belonging to various genera (Bacillus, Enterobacter, Pantoea, Erwinia and Stenotrophomonas) were isolated and identified. Total phenolic contents and total flavonoids contents varies among all the bacterial extracts respectively in which Bacillus subtilis showed high phenolic contents 243 µg/mg of gallic acid equivalents (GAE) and Stenotrophomonas maltophilia showed high flavonoids contents 15.9 µg/mg quercitin equivalents (QA), total antioxidant capacity (TAC) 37.6 µg/mg of extract, reducing power (RP) 206 µg/mg of extract and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity with 98.7 μg/mL IC50 value. Although all the extracts tested were active to inhibit growth of selected pathogenic microbes (bacteria and fungi), but significant antibacterial activity was observed against Klebsiella pneumonia and B. subtilis. An Enterobacter cloaca was active against Leishmania tropica with IC50 value of 1.4 µg/mg extracts. B. subtilis and Bacillus tequilensis correspondingly exhibit significant protein kinase inhibition of 47 ± 0.72 and 42 ± 1.21 mm bald zones, indicating anti-infective and antitumor potential.ConclusionsOur findings revealed that crude extracts of selected endophytic bacteria from F. indica possess excellent biological activities indicating their potential as an important source of antibiotics (antifungal, antibacterial) compounds.

Antimicrobial and Antioxidant Properties of Fruits of Capsicum annuum var. cerasiforme (Mill.) Irish and Heracleum nepalense D. Don

The fruit of Capsicum annuum var. cerasiforme belonging to the Family Solanaceae is a widely used spice in Sikkim, a North Eastern state of India. The fruit of Capsicum annuum var. cerasiforme locally called ‘Dalle Khorsani’ is a valuable cash crop of Sikkim and also possess medicinal properties. Heracleum nepalense D. Don locally called ‘Chimphing’ belongsto the Family Umbillifereae and is extensively used in folk medicine. The present study evaluated the antimicrobial property of fruits of Capsicum annuum var. cerasiforme (Mill.) Irish and Heracleum nepalense D. Don using agar well diffusion method against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris, Staphylococcus aureus, Bacillus cereus and Bacillus subtilis. The antioxidant property of methanol extracts of fruits of these test plants was also investigated. The antioxidant property was evaluated by 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical scavenging activity assay and Ferric reducing power assay. The total phenolic content was determined by using Gallic acid as a standard. The methanol extract of both the plants inhibited the growth of mostly Gram positive bacteria and Escherichia coli among Gram negative bacteria. However the acetone extract of the selected plants did not exhibit antimicrobial activity. The methanol extracts of these plants exhibited significant (p>0.05) concentration dependent increase in DPPH free radical scavenging activity. The extract of Capsicum annuum var. cerasiforme (Mill.) Irish also exhibited significantly higher (p>0.05) ferric reducing ability thereby showing higher antioxidant activity. The phytochemical analyses of the plant extracts revealed the presence of phenol, tannin, flavonoid, alkaloid, steroid and saponin. The results of the present study indicate that Capsicum annuum var. cerasiforme (Mill.) Irish and Heracleum nepalense D. Don can be a potential source of antimicrobial and antioxidant agents and can be explored further for its therapeutic use.

Bioactive Chemical Constituent Analysis, in vitro Antioxidant and Antimicrobial Activity of Whole Plant Methanol Extracts of Ulva lactuca Linn

Aims: To analyse the bioactive chemical constituents and evaluate in vitro antioxidant and antimicrobial activities of whole plant methanol extracts of Ulva lactuca Linn. Study Design: Preliminary phytochemical screening, Gas Chromatography-Mass Spectrometry (GC-MS) analysis, evaluation of antioxidant and antimicrobial activities. Place and Duration of Study: Veterinary University Training and Research Centre, Ramanathapuram-623503, Department of Botany, A.V.V.M Sri Pushpam college, Poondi, Thanjavur-613503 and K.M.C.H college of pharmacy, Kovai Estate, Kalapatti Road, Coimbatore-641048. The studies were carried out during August-December 2016. Methodology: Phytochemical constituents were identified by qualitative and GC-MS analysis. In vitro antioxidant activity of the extracts were studied using DPPH radical scavenging assay, total phenol and total flavonoid content determination assays. Antimicrobial activity was investigated by disc diffusion technique. Results: Phytochemical screening of methanol extracts showed positive results for alkaloids, flavonoids, phenols, tannins, terpenoids, glycosides, steroids, proteins and negative results for saponins and cardiac glycosides. GC-MS analysis revealed the presence of 10 compounds in Ulva lactuca methanolic extracts and some of the phytocomponents screened were terpenoids, fatty acid derivatives and aliphatic hydrocarbons and many of them have antioxidant, anti-inflammatory, antimicrobial and anticancer actions. Methanolic plant extract showed significant antioxidant activity under DPPH free radical scavenging activity, total phenol and total flavonoid content determination assay. In disc diffusion technique among six bacterial species, methanol extract showed potent activity against three Gram positive (Bacillus subtilis, Corynebacterium diphtheriae and Staphylococcus aureus) and three Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Salmonella paratyphi). The extracts were more potent towards fungal isolates (Aspergillus niger and Aspergillus fumigatus) and no activity reported in Candida albicans. Conclusion: The results demonstrate that methanolic extracts of whole plant of U. lactuca can be used as a potential source of antioxidant and antimicrobial agent.

Antilipase and antioxidant activity of Orthosiphon stamineus methanolic extract

Introduction: Antilipase from natural resources are a potential tool for the treatment of obesity while antioxidant-rich plants are essential in combating degenerative diseases. The aim of this study is to determine the antilipase and antioxidant activity of Orthosiphon stamineus methanolic extract. Methods: The inhibitory activity against pancreatic lipase was determined by measuring the hydrolysis of p-nitrophenyl butyrate to p-nitrophenol at 405 nm. Antioxidant activity of O. stamineus extract was measured by 2, 2, diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay. Results: The O. stamineus crude extract exhibited strong lipase inhibitory activity with an IC50 value of 34.7 µg/ml. The inhibition mode study disclosed that O. stamineus could act as uncompetitive inhibitor. O. stamineus showed high antioxidant activity with an EC50 value of 26.3 µg/ml. Conclusions: The results suggest that O. stamineus has shown potential as a source of natural antilipase and antioxidant.

Comparative analysis of two thioredoxin-like genes in black rockfish Sebastes schlegelii and their possible involvement in redox homeostasis and innate immune responses

Elevated levels of ROS can cause serious intracellular damages by reacting readily with nucleic acids, proteins and lipids, thus triggering tissue damage and cell death. Thioredoxin system is one of the principal factors that maintain the intracellular redox balance via its antioxidant property. In this study, we characterized two new thioredoxin isoforms (SsTXN-like 1 and SsMtTXN-like) from black rockfish, Sebastes schlegelii. The molecular and structural characteristics, as well as the evolutionary relationships of SsTXN-like 1 and SsMtTXN-like confirmed that they belong to the thioredoxin superfamily. A classical thioredoxin domain was found in both proteins with a conserved redox-active site CXYC, however, only the precursor of SsMtTXN-like protein possessed a mitochondrial targeting signal. The results from insulin disulfide reduction activity assay demonstrated that their recombinant proteins are capable of reducing the disulfide bonds of oxidatively damaged proteins via their oxidoreductase activities. The free radical scavenging activity assay revealed the prominent hydroxyl and DPPH scavenging activities of rSsTXN-like 1 and rSsMtTXN-like in a dose-dependent manner. Transcriptional studies showed a broad distribution of SsTXN-like 1 and SsMtTXN-like transcripts in all the examined tissues. Significant (p < 0.05) up-regulations of both genes in immune-related tissues after LPS, poly I:C and Streptococcus iniae challenges reflect their critical role in redox homeostasis in black rockfish. Taken together, SsTXN-like 1 and SsMtTXN-like, as two active members of thioredoxin superfamily, have significant antioxidant properties to housekeep the redox potential during various stress conditions and innate immune response of Sebastes schlegelii.

Cryptoporic acid S, a new drimane-type sesquiterpene ether of isocitric acid from the fruiting bodies of Cryptoporus volvatus

A new drimane-type sesquiterpene with an isocitric acid moiety, cryptoporic acid S (1), together with six known compounds, cryptoporic acid D (2), β-sitosterol (3), β-daucosterol (4), stigmast-4-en-3-one (5), ergosterol (6), and (22E,24R)-ergosta-7,22-diene-3β,5α,6β-triol (7), was isolated from the fruiting bodies of Cryptoporus volvatus. The structures of these compounds were established on the basis of UV, IR, MS, 1D and 2D NMR analysis. In the meanwhile, compounds 1 and 2 were evaluated for antioxidant activity using the methods of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH-RSA) and ferric reducing antioxidant power (FRAP) assay, and they exhibited moderate antioxidant activities.

Chemical Composition, Antibacterial and Antioxidant Activities of Essential Oils from the Aerial Parts of Ferulago angulata (Schlecht.) Boiss and Ferulago bernardii Tomk. & M. Pimen from Different Parts of Iran

The objective of the current study was to evaluate chemical composition, antioxidant and antibacterial activities of essential oils from the aerial parts of Ferulago angulata (Schlecht.) Boiss and Ferulago bernardii Tomk. & M. Pimen collected from four different parts of Iran (Ilam, Lorestan, Kermanshah and Kurdestan regions). The chemical compositions of the essential oils were identified by means of gas chromatography coupled with mass spectrometer detector (GC-MS). The antimicrobial activities of the essential oils were examined by micro-dilution method and agar disk diffusion assays. The antioxidant activities were measured by DPPH free radical scavenging activity assay. α-Pinene was the most abundant component in oil samples of Ilam, Lorestan and Kermanshah regions represented by 35.03%, 34.45% and 28.43%, respectively, but Z-β-ocimene was the most abundant component in oil obtained oil from Kurdestan samples (27.9%). The essential oils exhibited moderate level of antibacterial activity against the test microorganisms. E. feacalis followed by M. luteus, were the most sensitive bacteria. The most resistant bacterium was K. pneumoniae. The essential oil of F. angulata collected in Kurdestan region showed the most antibacterial activity against growth of all tested bacteria. In the case of DPPH assay, the essential oil of Lorestan sample had the highest activity (IC50 = 11.70 ± 0.217 mg/ml) followed by Ilam (IC50 = 14.13 ± 0.526 mg/ml), Kurdestan (IC50 = 14.87 ± 0.248 mg/ml) and Kemanshah (IC50 = 16.90 ± 0.214 mg/ml) oil samples. The IC50 value of quercetin was 4.96 ± 0.026 μg/ml. Our findings indicate that F. angulata and F. bernardii essential oils have potentials to be applied as antimicrobial and antioxidant agents.

Antioxidant and acetylcholinesterase inhibitory activities of leaf extract and fractions of Albizia adianthifolia (Schumach) W.F. Wright.

This study was conducted to determine the antioxidant and acetylcholinesterase inhibitory activities of the leaf extract and different fractions of Albizia adianthifolia (Schumach.) W. Wright, and also to identify and quantify some phenolic compounds in the extract. The antioxidant and acetylcholinesterase inhibitory activities of the methanol extract (CME), ethyl acetate (EAF), chloroform (CHF), and n-hexane (NHF) fractions of A. adianthifolia leaves were subjected to in vitro chemical analyses. Phytochemical screening revealed important classes of secondary metabolites. All extracts showed good antioxidant and acetylcholinesterase inhibitory activities. The EAF and CHF gave the highest total phenolic contents of 18.02±0.14 and 18.43±0.95 mg gallic acid equivalent per gram of extract, respectively. The polar extracts gave the highest activity in both assays with lower IC50 values. In the 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging activity assay, the IC50 values of CME, EAF, CHF, and NHF were 77.74±0.84, 55.76±2.30, 58.47±0.72, and 232.24±2.70 µg/mL, respectively, while in the acetylcholinesterase inhibitory assay, the IC50 values of CME, EAF, CHF, and NHF were 11.80±0.88, 10.04±1.67, 17.44±1.74, and 124.38±1.51 µg/mL, respectively. The results of this study suggest that the leaf of A. adianthifolia could serve as a potential candidate for future search of antioxidant and acetylcholinesterase inhibitors for the management of neurodegenerative disorders such as Alzheimer's disease.

Chemical Composition and Antioxidant Activity of Essential Oil from Torreya grandis cv. merrillii Arils

This study was to investigate the chemical composition and the antioxidant activity of essential oils extracted from Torreya grandis cv. merrillii arils by hydro-distillation. Eighty six compounds, accounting for 96.39% of the essential oil, were identified by GC-MS. The essential oil contained 42 sesquiterpenoids (68.91%), 25 monoterpenoids (14.52%), 14 diterpenoids (12.39%), 3 ester (0.35%), 1 aliphatic ketones (0.04 %), and 1 aliphatic aldehyde (0.18%). The major components of the oil were Δ-cadinene, germacrene D, limonene, β-farnesene, cembrene, and α-pinene. Antioxidant activities of the essential oil was determined by 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity assay (IC50=17.13 mg/ml), β-carotene/ linoleic acid bleaching method (IC50=22.48 mg/ml), and thiobarbituric acid reactive species assay (IC50=13.48 mg/ml). These various antioxidant activities were compared with synthetic antioxidants (butylated hydroxytoluene and acorbic acid). Restults revealed that the essential oil possessed strong antioxidant activity, suggesting that the arils of Torreya grandis cv. Merrillii could be a bio-resource for an essential oil with antioxidant activity.

Biological activities of four Parmotrema species of Malaysian origin and their chemical constituents

The present study was carried out to evaluate the antibacterial and antioxidant potential of acetone and methanol extracts of lichen (Parmotrema praesorediosum, P. rampoddense, P. tinctorum and P. reticulatum) and isolated chemical constituents which are praesorediosic acid, protocetraric acid, usnic acid, α–collatolic acid, β-alectoronic acid, atranorin and chloroatranorin. The antibacterial activity was evaluated using broth dilution method. Acetone extracts (except for P. reticulatum) showed good inhibitory activity against S. aureus and B. subtilis with MIC values ranging from 500–125 µg/mL, whereas, no activity was observed for the methanol extracts. Extracts exhibited zero inhibitory activity against E. coli. The antioxidant ability was measured using a DPPH free radical scavenging activity assay. Only methanol extract of P. praesorediosum exhibited more than 50% scavenging activity. Among the isolates, usnic acid exhibited the strongest antibacterial activity against S. aureus and B. subtilis with MIC value 7.81 µg/mL. Praesorediosic acid and protocetraric acid isolates exclusively inhibited E. coli at concentration 125 µg/mL and displayed results exceeding 50% scavenging activity (57.57% and 63.97%, respectively). Hitherto, it is the first evaluation of antibacterial activity on lichens of Malaysian origin and to our knowledge; the first reported study on the biological activity of praesorediosic acid and Parmotrema rampoddense.

PRELIMINARY PHYTOCHEMICAL SCREENING AND IN VITRO ANTIOXIDANT ACTIVITY OF ETHIOPIAN INDIGENOUS MEDICINAL PLANTS, OCIMUM LAMIIFOLIUM HOCHST. EX BENTH AND OCIMUM BASILICUM L.

Antioxidants are the chemical substances which prevent the free radicals damage in the body. Numerous researches are going globally focussed on investigating natural antioxidants of plants origins. The aims of the present study were to evaluate preliminary phytochemical investigation and in vitro antioxidant activities of Ethiopian indigenous medicinal plants, Ocimum lamiifolium Hochst. ex Benth and Ocimum basilicum L. Aqueous, benzene and hexane crude leaves extracts of O. lamiifolium and O. basilicum were subjected to qualitative phytochemical screening using standard procedures. In addition, we investigated the antioxidant potential of crude aqueous leaves extract of O. lamiifolium and O. basilicum using tests involving inhibition of superoxide anions, DPPH, H2O2, NO and ABTS. Preliminary phytochemical investigation for benzene, hexane and aqueous extracts found alkaloids, sterols, carbohydrate and glycosides, tannins and flavonoids. The fraction inhibition of lipid peroxide at the first stage of oxidation illustrated antioxidant activity of O. lamiifolium and O. basilicum as 90% and 88% compared to those of gallic acid (97%) and BHT (84%) respectively. Also, the aqueous leaves extract of O. lamiifolium and O. basilicum exhibited significant DPPH free radical scavenging activity, nitric acid free radical scavenging activity assay, superoxide anion scavenging activity, ABTS scavenging activity and hydrogen peroxide free radical scavenging assay. Our findings provide confirmation that the aqueous leaves extract of O. lamiifolium and O. basilicum are potential source of natural antioxidants, and this warranted its uses in traditional medicine systems.

DPPH Free Radical Scavenging Activity, and their Synthetic, Structural, Electronic and Magnetic Studies of Two [CuII2(thb)] Compounds, (thb= N,N,N´,N´-tetrakis-{3-[(2-hydroxibenzyliden)-amine]propyl}-1,4-butanodiamine)

Synthesis, structural, electronic, and magnetic characterization of two [CuII 2(thb)] (thb = N,N,N’,N’- tetrakis-{3-[(2- hydroxibenzyliden)-amine]propyl}-1,4-butanodiamine)]) crystalline phases (1a and 1b) are reported. Both, 1a and 1b, showed free radical scavenging activity, which was quantified by the DPPH free radical scavenging activity assay. 1b crystallized in a P21/c space group. In 1b each molecule contains two CuII-(hidroxibenzyliden) groups bonded in the extremes of the organic DAB-Am nucleus. The CuII-(hidroxibenzyliden) groups of each extreme, form 1D chains along of the b-axis. IR and UV-Vis spectra showed d-d transitions and νCu-O, νCu-N vibrations respectively, confirming the formation of the compound. 1H-NMR spectra of 1a and 1b showed similar spectra, being characteristics of paramagnetic compounds. Bulk magnetization of 1a and 1b from 2 K to 300 K showed paramagnetic behaviour. The best fit for the susceptibility data was obtained using Curie-Weiss and modified Curie-Weiss equations with θ and C values of θ1a/1b C-W = 0 ± 1K, C1a/1b C-W = 0.82/0.66 cm3 K mol-1, and θ1a/1b modified C-W = 0.6 ± 1K and C1a/1b modified C-W = 0.80/0.70 cm3 K mol-1. The X-band ESR spectra of 1a and 1b in solid samples showed a single and a rhombic signals, respectively, with g values around 2.1 at 77 K and 300 K, however, in CH2Cl2 solutions at 77 K the spectra were similar. The spectroscopic and magnetic results allowed us to conclude that 1a and 1b are two different crystalline phases which were proven to act as effective antioxidants showing both an IC50 = 16.5 μM, in contrast with Trolox, IC50 = 39.3 μM, normally used as a vitamin E analog and a strong antioxidant. Additionaly the DPPH free radical is scavened by reduction mechanism of CuII to CuI. The overall electronic, magnetic and structural information about 1a and 1b provide us some characteristics of this kind of transitional metal ionic coordination compounds.

Anticonvulsant and in vitro antioxidant activities of Momordica cissoides L. (Cucurbitaceae)

Review on Ethanomedicinal and Pharmacological Properties of Ficus religiosaAmandeep Kaur, A. C. Rana, Vineeta Tiwari, Ramica Sharma, Sunil Kumar

Watermelon Seeds as Food: Nutrient Composition, Phytochemicals and Antioxidant Activity

Watermelon (<i>Citrullus lanatus</i>) seeds are often discarded while the fruit is eaten. In this study, seeds of three (3) varieties of watermelon (Charleston gray, Crimson sweet and Black diamond) were analyzed for their proximate, minerals, phytochemicals, total phenols content and antioxidant activity. The proximate analysis and phytochemicals screening were performed using standard procedures whereas minerals content was determined by atomic absorption spectrophotometry. DPPH free radical scavenging activity and Folin-ciocalteau assays were used to determine antioxidant activity and total phenol content, respectively. The results indicated that the watermelon seeds had moisture content in the range of 7.40 - 8.50%; fat, 26.50 - 27.83%; protein, 16.33 - 17.75%; fibre, 39.09 - 43.28%; ash, 2.00 - 3.00%; carbohydrate, 9.55 - 15.32% and energy value of 354.05 - 369.11 kcal/100g. The seeds also contained appreciable minerals (Ca, P, Mg, Na, K and Zn) with K (3.40-3.5 mg/100g) being the highest while Na (0.07 - 0.08 mg/100g) was the least. DPPH% inhibition varied between 59.88-94.46% inhibition with trolox equivalent of 82.59-130.29 µM/g depending on the variety. Saponins, tannins, triterpenoids glycosides and alkaloids were present in all samples. Crimson sweet seeds had the highest total phenol content (5416 mgGAE/100g), followed by Black diamond (3949 mg GAE/100g) and the least, Charleston gray (1494 mg GAE/100g). Similarly, Crimson sweet had the highest antioxidant activity, followed by Black diamond and lastly, Charleston gray. The present findings suggest watermelon seeds as considerable source of nutrients in the diet and may have health and economic benefits due to its fibre, minerals, phenolics content and antioxidant activity.

Antimicrobial, Antioxidant and Hemolytic Activity of Water-soluble Extract of Mottled Anemone Urticina crassicornis

We evaluated the biological activities of five water extracts of tissue of the mottled anemone Urticina crassicornis. Most extracts exhibited broad-spectrum antimicrobial activity as determined by ultrasensitive radial diffusion assay (URDA) against gram-positive and -negative bacteria, including a fish pathogen, Aeromonas hydrophila, but no activity against fungi. The activity of the extracts was abolished by tryptic digestion, indicating that protein compounds were responsible for the antimicrobial activity. Furthermore, in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity assay, only the visceral tissue extract showed activity. However, no extract had hemolytic activity against human red blood cells. Consequently, this study suggests the water-soluble extract of mottled anemone to be a promising source of proteinaceous antimicrobial compounds that can be utilized for development of novel antibiotics.

Total phenolic content, antioxidant activity and pre-clinical safety evaluation of an Anacardium occidentale stem bark Portuguese hypoglycemic traditional herbal preparation

Anacardium occidentale L. (cashew tree) has been traditionally used to treat type 2 diabetes. Hereby we present results of free radical scavenging activity assay and in vivo toxicity and genotoxicity tests on red and white cashew stem bark Portuguese traditional herbal preparations (CSBTHPs) used to control type 2 diabetes, standardized on the basis of the total phenolic content.A 2-week repeated dose toxicity study was performed with three doses (40.2, 127, 402mg/kg/day) of each CSBTHP, administered by gavage to CD-1 mice (n=28). Micronucleus test and comet assay were performed in CD-1 mice (n=18) which received a single dose of 2000mg/kg (p.o.) of each CSBTHP or cyclophosphamide 50mg/kg (i.p.) or water (p.o.).The total phenolic content was 58.0±0.4mg gallic acid equivalents (GAE)/g cashew stem bark (CSB) in white CSBTHP and 51.3±1.6mg GAE/g CSB in red CSBTHP. Both red and white CSBTHPs exhibited concentration-dependent radical scavenging activity with IC50 values of 180.7±6.7μg/mL and 143.8±2.8μg/mL, respectively. No treatment-related effects on relative organ weights, biochemical parameters and food intake were observed in the repeated dose toxicity study with both CSBTHPs. In the mice micronucleus test both CSBTHPs showed absence of bone marrow suppression and a similar frequency of micronuclei in immature erythrocytes between treated and negative control groups. The comet assay revealed both CSBTHPs to be non-genotoxic.Concluding, both red and white CSBTHPs, standardized on the basis of the total phenolic content, revealed to be sources of natural antioxidants and devoid of a genotoxic risk. The daily oral administration of doses up to 402mg/kg of those CSBTHPs did not induce relevant signs of toxicity in mice.

Antioxidant compounds and antioxidant activities in unripe and ripe kundang fruits (Bouea macrophyllaGriffith)

Introduction. Kundang fruit (Bouea macrophylla Griffith) is very popular in Malaysia and other ASEAN countries. The fruit is traditionally believed to impart potential health benefits, but no scientific information is available on the antioxidant compounds or the antioxidant activities in unripe and ripe kundang fruits. Materials and methods. Unripe and ripe kundang fruits were freeze-dried and subjected to three different types of solvent extraction (methanol, ethanol and distilled water). Freeze-dried samples were individually evaluated for antioxidant compounds (total phenolics, tannins, flavonoids and flavonols) and antioxidant activities (ferric reducing antioxidant power assay/FRAP assay, ABTS−+ assay and DPPH. free radical-scavenging activity assay). Results and discussion. High contents of phenolics, tannins and ascorbic acid were found in unripe fruits (extracted with methanol), whereas flavonoids and flavonols were high in ethanolic extracts. Anthocyanins were the highest in ethanolic extracts of ripe fruits. In addition, methanolic extracts of unripe fruits showed the highest antioxidant capacity [16,290.91 ¯M Fe (II) 100 g-1 ], with 77.69% DPPH inhibition and 99.76% ABTS.+ radical scavenging activities. Conclusion. This study clearly indicated that solvents tend to influence the extractability of antioxidant compounds. Overall, the results of this study can be of practical use in providing sufficient information on the presence of various antioxidant compounds in kundang unripe and ripe fruits, which could be commercially exploited for developing various healthy food formulations.

Antioxidant components and properties of dry heat treated clove in different extraction solvents.

The effects of heat treatment and extraction solvents (pure/aqueous acetone, ethanol, methanol) on antioxidant activity (AA) and components of clove (Syzygium aromaticum Linn) were studied. Clove was subjected to dry heat treatment (microwave and roasting) and the AA measured by free radical scavenging activity (FRSA), reducing power (RP), and phospho-molybdenum assay (TAA). Unheated samples served as controls. The antioxidant components estimated were total phenols, flavonoids and tannins. Using RP and FRSA, highest AA was observed in 80% acetone extract of all samples (1.778-1448 and 84.5-86.0%). TAA showed higher value in 80% methanolic extract for all samples in the range 303.595-307.941mmol ascorbic acid/g. Heated samples exhibited higher AA in all assays. Highest amount of phenols and flavonoids were extracted in 80% acetone (4053-4064mg/100g) and 80% methanol (11,271-11,370mg/100g) respectively. For tannins, maximum extraction was in 80% acetone (control, 16441mg/100g), 80% ethanol (microwave, 19,558mg/100g), and pure methanol (roasted, 15,823mg/100g). Total phenol and flavonoid contents were positively associated with AA determined using RP and FRSA. In conclusion, clove exhibited powerful AA in different extraction solvents which increased on dry heat treatments and correlated positively with antioxidant components. Hence, clove can be used as a natural antioxidant in food systems.

Extraction of bilberry (Vaccinium myrtillus) antioxidants using supercritical/subcritical CO2 and ethanol as co-solvent

Anthocyanins and other phenolic compounds of bilberry (Vaccinium myrtillus) are known for their antioxidant properties. Supercritical (SC) and subcritical (SubC) CO2 extractions have been used to improve extraction and selectivity of plant bioactive compounds. Bilberry was extracted by SC CO2 followed by SubC CO2 with 10% v/v ethanol as co-solvent. Total phenolic compounds, anthocyanins and proanthocyanidins were quantified and chemically characterized by HPLC-DAD-ESI-MS/MS. Antioxidant activity was tested by reducing power assay, free radical scavenging activity (DPPH) and ABTS radical cation assay. SubC CO2 selectively extracted cyanidin-3-O-glucoside and cyanidin-3-O-arabinoside. Delphinidin-3-O-glucoside, ellagic acid pentoside, feruloyl hexoside and several quercetin glycosides were also extracted. SubC CO2 extracts showed a high antioxidant activity [DPPH IC50=102.66 (±2.64); ABTS IC50=8.49 (±0.41) and reducing power activity IC50=10.30 (±0.10)]. SubC-CO2 extraction of bilberry is an efficient method to recover selectively compounds with a high antioxidant activity and a high potential for pharmacological applications.

Antioxidant and anti-inflammatory activites of Clerodendrum leaf extracts collected in Thailand

IntroductionClerodendrum plants have been traditionally used for inflammatory related diseases in Thailand. Crude extracts of Clerodendrum disparifolium and Clerodendrum laevifolium were assessed for antioxidant and anti-inflammatory activities in order to support traditional Thai claims about the therapeutic potential of these plants. MethodsEthanol and hexane extracts of leaves were evaluated for the in vitro antioxidant activity including phenolic content assay using Folin–Ciocalteu method, flavonoid content assay using an aluminium chloride (AlCl3) colorimetric method, 2, 2-Diphenyl-2-picryl-hydrazyl (DPPH) free-radical scavenging activity assay, total reductive capability assay, total antioxidant activity assay using ferric thiocyanate (FTC) and thiobarbituric (TBA) methods. In addition anti-inflammatory activity was assayed against lipoxygenase. ResultsThe phenolic and flavonoid contents, relating with their antioxidant activities, of the extracts ranged from 1167.21–3344.52 GAE/g of dry extract and 9.05–59.91mg QE/g of dry extract, respectively. Reducing power increased with increasing concentrations of extracts. The lipid peroxidation inhibition was evaluated by ferric thiocyanate (FTC) and thiobarbituric (TBA) methods, which demonstrated the maximum inhibition in ethanol C. laevifolium (55.49%) and C. disparifolium(96.17%) extracts, respectively. Furthermore the ethanol C. laevifolium extract exhibited highest 2, 2-Diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging activity (IC50 12.70μg/mL) and also possessed the greatest anti-inflammatory activity (IC50 14.12μg/mL). ConclusionsThis study indicated that selected Clerodendrum leaf extracts exhibited potential antioxidant and anti-inflammatory activities, which could be focus of further phytochemical research and may be applicable as natural medicine.